Hierarchical Metallized Polyimide Fiber for Flexible Supercapacitors with Ultra-High Capacity

Flexible supercapacitors show promising application prospects for portable electronic devices. It has the advantage of being charged/discharged at high rate, which is attributed to the ion storage on the electrode surface. However, this storage mechanism also brings low energy density. To improve the capacitance of supercapacitors when the energy storage device is bent has always been an important challenge. Here, we coated nickel (Ni) on the electrospun polyimide (PI) fiber to form a conductive nickel-coated nanofiber membrane (NNM). A flexible supercapacitor with ultrahigh specific capacitance was prepared through employing the current collector of the surface-metalized NNM. PI fibers with excellent mechanical properties can guarantee good flexibility. Additionally, the electrospun PI fiber shows a large specific surface area, and it also shows a high electrical conductivity after metallization. After depositing manganese dioxide, the NNM@MnO2 delivers both high capacity and power density (207.5 F/g at 50 mV/s). This hierarchical PI-based current collector is easily scaled up and exhibits excellent electrochemical performance, showing promising applications in the field of flexible supercapacitors.